The invention provides a perforation blasthole blocking method. The perforation blasthole blocking method comprises the steps that firstly, a full-seal bridge plug is put into the lower portion of a blasthole for setting; secondly, the leakage pressure and the water absorption capacity are determined through clear water pressure testing; thirdly, a coiled tubing is put to the plug face of the full-seal bridge plug, spacer liquid and inorganic gel are positively replaced, and the clear water is positively replaced; fourthly, the coiled tubing is lifted for cyclic well washing; fifthly, the clear water is positively squeezed to squeeze part of the inorganic gel into a stratum, the pressure is built, and waiting is conducted on cement setting; and sixthly, clear water pressure testing is conducted after the inorganic gel is solidified, micropores are blocked through dispersing glue if pressure drop is smaller than 10 MPa within 30 min, and the steps are repeated if the pressure drop is larger than 10 MPa within 30 min. By adoption of the perforation blasthole blocking method, the perforation blasthole in the fracturing process can be effectively blocked, the inorganic gel is high in pressure bearing capacity, can bear the effect of the high pressure of 120 MPa, and can meet the requirements of multi-section fracturing, the perforation blasthole blocking method is high in controllability, and site construction is easy.